Geant4 9.5 Release Notes
December 2nd, 2011

The code and binary libraries for the supported systems are available through our Source Code Web page.

We are grateful for the efforts of Geant4 users who have provided detailed feedback or comprehensive reports of issues. We thank in particular those who have contributed corrections, improvements or developments included in this release.

Please refer to the Geant4 User Documentation for further information about using Geant4.


  1. Supported and Tested Platforms
  2. Supported CLHEP version
  3. Items for migration of the user code
  4. New Developments and Capabilities
  5. Expected effects on physics and performance
  6. Known Run-Time Problems and Limitations
  7. Compilation Warnings
  8. Known Run-Time Warnings
  9. Geant4 Software License
  10. Detailed list of changes and fixes

1. Supported and Tested Platforms

Officially tested platforms: More verified configurations: Platforms configured but neither tested nor supported:

2. Supported CLHEP version

This release of Geant4 has been verified with CLHEP, release Use of a different CLHEP version may cause incorrect simulation results.

3. Items for migration of the user code

Listed here is some relevant information on developments included in this release, some of which may require migrations (mainly for users of advanced Geant4 features) in order to upgrade from release 9.4 to release 9.5. Note that for all users a full re-installation of libraries (or a full recompilation) and a recompilation of user applications is required.


Standard Electromagnetic physics

Low Energy Electromagnetic physics


Physics Lists

Use of Exceptions

Data Sets

This release introduces new data set versions. Please see the corresponding details in Section 10 of this document.

4. New Developments and Capabilities

Geometry Materials Standard Electromagnetic physics Hadronic physics

Interfaces and Visualization

Physics Lists

5. Expected effects on physics and computing performance

Standard Electromagnetic physics and cuts Hadronic physics

6. Known Run-Time Problems and Limitations

For a complete list of outstanding run-time problems and to submit any problem you may find while running this version of Geant4, please refer to the Geant4 Problem Reporting System.

7. Compilation Warnings

There may be a few compilation warnings on some platforms. We do not believe that any of these lead to incorrect run-time behaviour.

8. Known Run-Time Warnings

The following message may be written to standard output at the end of a program:
    G4Transportation: Statistics for looping particles 
       Sum of energy of loopers killed: 
       Max energy of loopers killed: 
It provides the total energy (in MeV) of tracks killed due to excessive number of steps ('looping') during the simulation, and the maximum energy of such a track. Such behaviour can be due to low-momentum particles which loop in magnetic fields (a physical effect, which can consume a lot of CPU time for little ) or being abandoned due to being stuck at geometrical boundaries.

In case either of these reported energies is significant, we recommend increasing the verbosity of G4Transportation to obtain information for each track killed. A user can change the threshold energy above which particles are killed more reluctantly (only after significant additional effort) using the method SetThresholdImportantEnergy() of G4Transportation. The default value is 100 MeV.

9. Geant4 Software License

A Software License applies to the Geant4 code. Users must accept this license in order to use it. The details and the list of copyright holders is available at and also in the text file LICENSE distributed with the source code.

10. Detailed list of changes and fixes

These are the main new features/fixes included in this release since the last patched public release (for more detailed lists of fixes/additions, please refer to the corresponding History files provided in most packages):



Digitization & Hits

Electromagnetic Processes

  • DNA:
  • High Energy
  • Low Energy
  • Muons
  • Precise Impact Ionisation
  • Standard
  • Utils
  • Xrays
  • Error Propagation




    General Processes



    Graphical Representations

    Hadronic Processes






    Physics lists


    Track & Tracking



    Data sets